Aerosol fire extinguisher and method

ABSTRACT

There is provided an improved aerosol-type fire extinguisher which is characterized by a metallic bottle having a yield point of about 800 psi, a riser pipe, a coupler to which is secured the riser pipe and the bottle, refilling valve means which are normally closed at the outer extremity of the coupler, a nozzle means including separate valve means therein including an internal shoulder which during attachment of the nozzle to the assembly opens the refilling valve. The fire extinguishing composition contained therein is characterized, first, by its stability in the presence of aluminum metal and, secondly, by being a mixture of a tetrahalo-substituted methane including at least one atom each of chlorine, fluorine, and bromine, and a tetrahalogenated methane including atoms of only chlorine and fluorine, which composition is a solvent for an inert gas, e.g., CO2. This composition when homogeneously blended together is then mixed with a sufficient quantity of inert gas under pressure, forming a solution therewith when maintained under super atmospheric pressure within the fire extinguisher, and far less demanding as to the strength of container than CO2 gas extinguishers. The novel method contemplates filling and refilling the fire extinguisher container by a process which includes blending the two halomethane components to form a homogeneous blend and then introducing carbon dioxide to the homogeneous blend under pressure or, alternatively, introducing the carbon dioxide into one of the tetrahaloalkanes first and then adding the other tetrahaloalkanes.

United States Patent 11 1 I Becker et al.

[541 AEROSOL FIRE EXTINGUISHER AND METHOD Inventors: James R. Becker, 2984 Essex Road, Cleveland Heights, Ohio 44118; Richard H. Furlow, 4701 Jefferson Street,'Midla'nd, Mich. 48640 Primary'Examiner M. Henson Wood, Jr. Assistant Examiner-John J. Love Attorney-l-larold F. McNenny et-al.

57 ABSTRACT There is provided an improved aerosol-type fire extinguisher which is characterized 1 by a metallic bottle H lMarch 20, 1973 having a yield point of about 800 psi, a riser pipe, a

coupler to which is secured the riser pipe and the bottle, refilling valve means which are normally closed at the outer extremity of the coupler, a nozzle means includingseparate valve means therein including an internal shoulder which during attachment of the nozzle to the assembly opens the refilling valve. The tire extinguishing composition contained therein is characterized, first, by its stability in the presence of aluminum metal and, secondly, by being a mixture of a tetrahalo-substituted methane including at least one atom each ,of chlorine, fluorine, and bromine, and a tetrahalogenated methane. including atoms of only chlorine and fluorine, which composition is a solvent for an inert gas, e.g., CO This composition when homogeneously blended together is then' mixed with a sufficient quantity of inert gas under pressure, forming a solution therewith when maintained under super atmospheric pressure within the fire extinguisher, and far less demanding as to the strength of container than CO gas extinguishers.

The novel method contemplates filling and refilling the fire extinguisher container by a process which includes blending the two halomethane components to form a homogeneous blend and then introducing carbon dioxide to the homogeneous blend under pressure 6 Claims, 1 l rawing Figure 1 AEROSOL FIRE EXTINGUISIIER AND METHOD BACKGROUND OF THE INVENTION AND PRIOR ART The present invention relates to fire extinguishers of sufficiently small size and economy to permit transportation and use in automobiles or aircraft and for general household use. Heretofore, fire extinguishers have tended toward the inert gas type or combinations of such inert gases .with water. These structures have tended to be rather large and heavy for containing sufficient extinguishing material to handle the normal conflagration encountered under the conditions set forth above, and hence there has been a real need for a relatively small-sized, economical, hand-operable fire extinguisher, using an inert gas as a propellant in solution in the extinguishing composition, but containable in a vessel having a yield pressure of 800 psi or less- There have recently been'developments in the field of flame-extinguishing compositions which are dependent upon haloalkanes or mixtures thereof. Typical of these is the US. Pat. to Gambaretto No. 3,479,286 and the US. Pat. to Glew No. 3,106,530. Theproblems with these compositions have been that the containers valve sleeve surrounds the valve body, and the valve body includes an externally accessible flanged portion.

Spring means are provided coacting between the valve sleeve and the flanged portion to bias the valve body in the normally closed position. Removable nozzle means,

preferably formed of plastic, are threadedly secured to the distal extremity of the coupler body and are provided withan internal shoulder adapted to engage and depress-the flanged portion to open' the refilling valve. The nozzle means include separate valve means and a spring-biased handle for opening and closing the nozzle valve in response to manual pressure. The fire extinguisher is completed by a liquid fire extinguishing com- .position contained within the bottle under pressure,

which composition is stable in the presence of the preferred aluminum and consists essentially of a heretofore available have normally been formed of materials which are sensitive to or unstable in the presence of the extinguishing composition, or sufficient propellant could not be introduced because of the limited strength of the container.

The present invention provides a fire extinguisher of sufficiently small size to be used in aircraft, automobiles, and homes, capable of containing under relatively low pressure a highly effective extinguishing compound containing dissolved therein an amount of inert gas sufficient to expel the composition and which composition has a vapor pressure of less than ll0 psi at ordinary temperatures, but in excess of about 35 psi. As

the inert gas propellant, there may be used, in order of preference, carbon dioxide, nitrogen, helium, or argon. It has also been discovered'that a more effective fire extinguisher may be prepared by filling and refilling the bottles of the present invention by a process which involves blending two different tetrahalogenated methanes to form a homogeneous mixture thereof, and subsequently introducing carbon dioxide 'under pressure, preferably with'agitation; or, alternatively, adding the inert gas, e.g. C0,, to the tetrahaloalkanes first, for example, just prior'to filling. The container with CO, may be used to achieve the desired pressure. It has also been found convenient to premix the'CO with both tetrahalogenated methanes and then add CO, to pressurize the can to a predetermined desired pressure.

BRIEF DESCRIPTION OF THE INVENTION homogeneous mixture of from 10 parts by weight of a tetrahalogenated methane containing at least one atom each of chlorine, bromine, and fluorine; from 90 10 parts by weight of a tetrahalogenated fluorochloromethane in which the halogen substituents.

are only fluorine and chlorine, the total of these halogenated methanes being parts by volume; and from 1 l2v parts by weight of inert gas, preferably C0,, dissolved therein.

In filling and refilling the fire extinguishers of the present invention, best results have been secured when the fully halogenated methanes are blended together initially, and the inert gas then introduced into the homogeneous mixture with agitation and under pressure. It is desirable that the mixture be agitated during introduction of the inert gas. It has also been found that the inert gas may be dissolved in one tetrahalogenated methane at a point remote from the filling site and this solution blended with the other tetrahalogenated methane, preferably with agitation and under pressure just prior to filling.

BRIEF DESCRIPTION OF THE DRAWINGS In the annexed drawing there is shown a partially cross-sectioned and partially cut away elevation of a fire extinguisher body in accordance with the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now more particularly to the annexed drawing, there is here shown in partial cross-section and partially cut away fire extinguisher body including an aluminum bottle 10 closed at its lower end by a cap '12 and provided with an internally threaded neck portion 14. Alternatively, an impact extrusion bottle having an integral end closure 12 may be used. An aluminum metal or plastic riser pipe 16 is centrally disposed within the aluminum bottle 10. The lower extremity 19 of the pipe 16 is disposed near, i.e. from about is to /4 inch, the bottom 12.

' An aluminum metal coupler body 18 is provided and threaded adjacent its lower extremity 20 for threaded engagement with the internal threads 22 of the neck 14. Coupler body. 18 may be crimpedinto place within the neck 14. Suitable ring seal means 24 may be provided to aid in retention of fluid and pressure within the bottle 10. An internal bore 26 is provided for receipt and frictional retention of the proximal extremity 28 of pipe 16(Also, elastomeric ring sealing means 30 may be provided. The bore 26and the extremity 28 may be threaded if desired.

The coupler body 18 includes intermediatethreads 32 for, receipt and retentionof a nozzle body 34 hereafter more particularly described. The distal extremity of the couplerbody 18 is provided with a cylindrical bore 36 into which is telescopically fitted a hollow cylindrical valve body 38 closed. at its lower extremity 40 by any suitable means such as a washer 42 over stud 44 threadedly retained within the cylindrical valve body 38 by a nut.46. Radial ports 50 and 52 allow for passage of fluid rising in riserpipel6 through the sidewalls of the hollow cylindrical valve body 38. The

upper'extremity of the valve body 38 is provided with a flange 54. The upper extremity of the'coupler body is provided with a recessed shoulder-56, and a coil spring 58 located in-the resulting recess between the shoulder 56 and the flange 54 to urge the valve body 38 into a normallyclosed position. Suitable peripheral seals 60 and 62 prevent loss of fluid in the clearance between the coupler body l8-andvthe telescopically movable valve body 38 and between the outer periphery of the coupler body 18 and the nozzle member 34.

The nozzle member is conveniently formed of plastic such as urea formaldehyde or Bakelitejand is desirably I ample 68 F. where the tetrahalomethanesare conport 70 within the nozzle '34 which is closed off by cylindrical valve 72 which is slidable in cylindrical bore 74. Suitable seals 76 and 78 are provided to prevent escape of fluid. The-valve 72 is provided with a seat portion 80 for seating coaction with valve seat 82 in nozzle body 34. A handle 84 is pivotally secured about pivot-86 and is provided with a projection 88 adapted for rolling coaction in slot 90 in the valve 72. To bias the valve 72 in a normally closed position against valve seat 82, there is provideda recess 92 in the handle portion 84, a rounded headed pin '94 mounted in socket 96,,and a biasing sprin'g'98 coactingbetween the botvTHE FIRE EXTINGUISHING COMPOSITION namely chlorine, fluorine, and bromine. Thus, the first component of the fre extinguishing composition may be CFgClBr, CChFBr, or CBr,F Cl or a mixture thereof. The second component of the fire extinguishtom of the recess 92 and the head of .the pin 94 to maintain the handle 84 in a fully extended position.

I then be forced through the riser 16 into thehollow in- I 4 ing composition is a methane derivative containing only chlorine and fluorine and is also tetrahalogenated.

Thus,the second component maybe CCl,F,, CCl F, or CClE or a mixture thereof. The third principal intogether. The propellant gas is then introduced under pressure and preferably with agitation; it is then uniformly dispersed and dissolved in the resulting composition and exhibits therein a vapor pressure at ordinary temperatures sufficient to expel the extinguishing composition at ordinary temperatures but well below the yield pressure of an economic container. .T he vapor bottle. The amount of gaseous CO, which would otherwise be required in other extinguisher systems would exceed the yield point of an'aluminum body of the economic dimensions useful with thepresent compositions.

The bromofluorochloromethane component is normally present in an amount ranging from 10 parts by weight and the chlorofluoromethane derivative normally present in a range of from 90 10 parts by weight, the summation of the tetrahalomethane components being parts by weight. A convenient mix-.

ture of the tetrahalomethanes is a 50-50 mixture by volume, and it is'preferred that the rangebe within the limits of 30 70 to 70 30. The amount of inert gas by volume. at standard conditions ranges from 1 12 parts. Normally from 8 10 parts by weight of carbon dioxide are incorporated, preferably in the manner aforesaid.

Filling and refilling of the fire extinguisher body-is normally accomplished at room temperatures, for exals are mutually soluble in all proportions and areconveniently blended under pressure initially. The inert gas is introduced under pressure; for example 15 atmospheres, through the neck of the bottle. If the bottle is agitated or shaken during the pressure introduction of inertgas, from 1 12 parts by weight of gas may be introduced into the composition. It has been found that when the carbon dioxide is introduced in thismanner, substantially improved consistency in fireextinguisher properties are observed, e.g., extinguisherpressure, rate of discharge and fire extinguishing action.

Filling and refilling is done through the valve in the coupler body by filling apparatus which depresses the cylindrical valve body 38. As-soon as the filling apparatus is removed, the spring 58 closes the valve by raising the valve body 38 so as to seal off the radial ports -50 and 52. The fire extinguisher assembly is completed by threadably securing the preformed plastic handle and nozzle portion to thecoupler body 18. Advancement of the nozzle 34 downwardly upon the coupler body 18 again depresses the cylindrical valve body 38 so that when the valve 72 is unseated, fluid retained within the bottle l0'under pressure may terior of the valve body 38 through the radial ports 50 and 52 into the opening 70 in nozzle body 34 and out the opening 100 in nozzle 34. At ordinary temperatures the pressure within the vessel is approximately 40 psi. At a temperature of approximately 150 F., the pressure is about 150 psi. These limits allow sufficient expulsion of the contents which are highly efficient fire extinguishing materials under a variety of temperatures such as may be encountered in use in an airplane or an automobile or a household without imposing any hazard at elevated temperaturesnormally encountered.

There has thus been provided an improved fire extinv guisher formed from aluminum and containing a highly efficient extinguishing composition which is substantially nonreactive with the container materials.,These extinguishers are of small size, easily carried, and handoperated and utilize an extinguishing'material of high tremity and having radially disposed port'means extending through the cylindrical sidewall adjacent the inner extremity of the valve body, cylindrical valvesleeve surrounding said valve body,

, saidvalve body including an externally accessible flanged portion, and spring means coacting between said valve sleeveand said flanged portion to bias said valve body in the normally closed position; V

. removable nozzle means threadedly secured'to the distalextremity-of said coupler'body' and having an internal shoulder adapted to engage and depress said flanged portion to open said refilling valve;

f. separate valve means in said nozzle means including a'valve body and a valve seat;

g. spring-biased means carried by said nozzle means for opening and closing said nozzle valve in response to manual pressure, and I h. a fire extinguishing composition'consisting essentially of a homogeneous mixture of:

1. from 10 to parts by weight of atetrahalogenated methane containing at least one atom each of chlorine, bromine, and

2. from 90 to 10 parts by weight of a tetrahalogenated fluorochloromethane in which the halogen substituents are only fluorine and chlorine, the total of l) and (2) being parts by weight; V

3. from 3 to 12 parts by weight of an inert gas selected from carbon dioxide, nitrogen, helium,

I and argon;

which composition has a vapor pressure less than about psi and greater than about '35 psi-at room temperature.

'2. A fire extinguisher in accordance with claim 1 wherein the inert gas is carbon dioxide.

3.. A fire extinguisher'in accordancewith claim 1 wherein the pressure-withstanding bottleis aluminum.

4. A fire extinguisher in accordance 'with claim 3 wherein the. pressure-withstanding bottle has a yield point of about 800 psi.

5. A fire extinguisher in accordance with claim 3 in which the aluminum bottle is impact extruded.

.A fire extinguisher in accordance with claim 1 wherein the fire extinguishing composition contains from 40 60 parts by weight of a tetrahalogenated methane containing at least one atom each of chlorine,

bromine, and fluorine; from 60 40 parts by weight of v a tetrahalogenated fluorochloromethane in-whi'ch the halogen substituents are only fluorine and chlorine, the

total of the two tetrahalogenated methanes being 100" parts by weight and from 8 '10 parts byweight of carbon dioxide. 

2. A fire extinguisher in accordance with claim 1 wherein the inert gas is carbon dioxide.
 2. from 90 to 10 parts by weight of a tetrahalogenated fluorochloromethane in which the halogen substituents are only fluorine and chlorine, the total of (1) and (2) being 100 parts by weight;
 3. from 3 to 12 parts by weight of an inert gas selected from carbon dioxide, nitrogen, helium, and argon; which composition has a vapor pressure less than about 110 psi and greater than about 35 psi at room temperature.
 3. A fire extinguisher in accordance with claim 1 wherein the pressure-withstanding bottle is aluminum.
 4. A fire extinguisher in accordance with claim 3 wherein the pressure-withstanding bottle has a yield point of about 800 psi.
 5. A fire extinguisher in accordance with claim 3 in which the aluminum bottle is impact extruded.
 6. A fire extinguisher in accordance with claim 1 wherein the fire extinguishing composition contains from 40 - 60 parts by weight of a tetrahalogenated methane containing at least one atom each of chlorine, bromine, and fluorine; from 60 - 40 parts by weight of a tetrahalogenated fluorochloromethane in which the halogen substituents are only fluorine and chlorine, the total of the two tetrahalogenated methanes being 100 parts by weight and from 8 - 10 parts by weight of carbon dioxide. 